Do you want to save an image with a transparent background? If you do then you should be aware that not all image formats support transparent backgrounds, and if you save your image in one that does not it will simply appear white.
That is why if you intend to save an image with a transparent background, you should use a few specific formats:
The GIF format was one of the more popular formats for transparency at one time. However it is limited to 256 colors, which makes it unsuitable for more complex images with lots of color tones.
More importantly GIF has since been surpassed by other formats in terms of its compression. As such its use is slowly diminishing, and it is only ever really chosen in casual settings.
Recently PNG has all but replaced GIF in most practical usage, and grown to be the most popular format for transparency. The PNG format exists in variants, the most notable being the PNG-8 that is limited to 256 colors, and the PNG-24 that supports millions of colors.
As you can imagine the PNG-8 variant is similar to GIF, but stores images in smaller files – which is why it is preferred. On top of that the PNG-24 variant can be used for more complicated images with diverse tones – such as photos.
The PNG-32 variant supports full alpha transparency that will let you vary the degree of transparency. That can allow you to create transparency gradients and more complex types of transparency.
One of the more recent formats to support transparency is WebP. It is designed to cater to web-based images, and uses lossless and lossy compression to reduce the file size of image files significantly.
Compared to PNG, WebP images can have up to 26% smaller file sizes while retaining the same quality.
The reason the WebP format isn’t as widely used as PNG (yet) is the fact that it still isn’t as widely-supported on browsers. However that it starting to change as both Firefox and Edge have announced upcoming support for WebP – and Chrome and Opera already support it.
If you use a photo background editor to remove the background and make it transparent, you will need to save it in one of the formats listed above for it to continue to be transparent. For example if you use Movavi Photo Editor you can choose between any of them.
It should be noted that there are other image formats that support transparency as well, such as BMP, TIFF, and JPEG2000. For various practical reasons they aren’t generally used, but you could consider them as well if you want to.
On top of that vector image formats support transparency as well, but are not the same as normal (i.e. raster) image formats.
Suffice to say the three formats listed above should cater to your needs if you want to save an image with a transparent background. Now that you know their features and limitations, it should make it easier to decide on one.